Spark-plug.



A. A.- DAVIS.

SPARK PLUG. I APPLIOATIOK FILED 0071.31. 1908.

Patented Apr.27,1909.

ZZrzca-a'ea 'of lillllOlS,

ARTHUR DAVIS, or CHICAGO,

UNrrED strA'rEs PA ENT orrion- ILLINOIS, ASSIGNORDF ONE-HALF T0 BENJAMIN GRIESHABER, OF CHICAGO, ILLINOIS.

SPARK-PLUG.

'lo all whomit may concern:

ie it known that l. Am'nt'u l).\\'is. a citizen of the lnited State residing at (hit-ago. in the eounty'of (ook have invented new and useful Improvements in Spark-Plugs. of which the following is a specification.

This invention relates to im rovements in spark plugs and it has for its 0 )jeot. broadly, toprovide a plug: which will at all times produce a large anduniform spark.

T he principal difiic-ulty with spark plugs is their-unreliability which i due mainly to the fact thatoil. soot and other foreign matter accumulate upon the terminals of the electrodes and prevent uniform sparking. This condition necessitatesfrequent cleaning of the electrodes or replacement of the plug. My invention aims to keep the terminals of the c'lectrmles' in a clean condition prepared at all times to. produce a large and uniform spark.

The invention also has for its objectto 7 construct the e ectrodes so that any oil or The battery wire 7 other foreign matter which may be deposited thereon will drain a'way'from both terminals and dischargeimpairing their-etiic-iency.

In the accompanying drawing 1 have shown a sectional view of a spark plug emlmdying the invention in one form and referring thereto. 1 is a casing ,andZ is a core of pm'celain. or other suitable insulating material. which is secured in the casing by a set not 3." conductor rod -l is arranged in the core and nuts 5 and 6 are screwed on tothe rod against opposite ends of the core.

may be engaged with the rod 4 between the not 5 and a nut 8 which is screwed on to the rod 4 to clamp the-.wire tightly against the nut The eleotrtxlest) and 10'are secured respectively I to the tflsing 1 and thenut 6 and they preferably 'xtend outward from the casing and nut iii-parallelism for a distance beyond the casing and their ends 11 and 12 are bent backward at sha acute angles 9'; 10' to bring the termina s 11'., 12' in op ositio'u to each other, preferably within t to casing,

although this is not essential. The opposing from the electrt'xles without Specification of Letters Patent. Application filed October 31, 3908.

Patented April 27, 1909.

Serial No. 60,876.

l iaces of the terminals are preferably made flat as shown. These spark plugs are usually secured in place in an upright position and thus it will be seen that any oil, soot. sweat or may be deposited on the electrodes will drain down to and be discharged from the points.

9'. 10'. leaving the terminals l1. l2 clean and constantly in rendition to 'produce'u' uniform spark. 'lhe terminals are located above the points 9'. 10' and an oil or foreign matter which flows from the casing or the nut (3 on to the electrodes will drain oil at the points without atfecting the terminals and if any oil or other foreign matter is deposited on the terminals it willftend to immediately flow down the inclined ends ll..- lz! away'from the terminals and to the points whence it is discharged.

'lhus. my invention provides a novel construction for the electrodes of a spark plug so that foreign matter will drain away from the terminal which are thereby maintained in a cleanly condition to produce a large and uniform s )ark at all times.

Whatclaim and desire to secure by lattel's Patentis:

other foreign matter which.

l. A spark plug comprising a pair of eleetrodes having their endsbent backward and provided with discharge points beneath the bonds of their terminals arranged in opposi-. tion to eaclrother.

2. 'A spark plug comprising a pair of electrodes arranged for a portion of their length in parallelism and having their ends bent backward and inward at an acute angle to i said parallel portions nals in op msition. r

3. spark plu comprising a pair of electrodes arranged or a n-tion of their length in parallelism and having their ends bent backward at an acute angle to said parallel" portions and novicled with discharge points beneath said ads and having their ternanals arranged in opposition to each other.,

' v ARTHUR Dav s.

\Vitne sses; r

' u. mm,- M. AJKmm-n.

and with their termi- 

